Kenya Civilians who had been hiding during a gun battle hold their hands in the air as a precautionary measure before being searched by armed police leading them to safety, inside the Westgate Mall, Sept. 21, 2013.

Jonathan Kalan/AP Photo

The terror group that claimed responsibility for the massacre at a Nairobi mall today warned the Kenyan government to remove their forces from Somalia or the mall attack would be "only the beginning."

"This Kenyan Government meddles flagrantly in Somalia's affairs; kills and displaces the Somali people; loots Somalia's riches and resources; and controls the simple life affairs in it," an alleged spokesperson for the group, al-Shabab, says, calling the mall attack a "blessed" operation.

"We give this warning to the Kenyan Government and those who side with it: If it wants to live peacefully and safely, it must withdraw from our country, stop meddling in our affairs, set our captives free, and denounce all forms of fighting our religion. If you refuse to do so, you have seen what you will reap, which is only the beginning," he said. "Thus, anticipate hard days."

The audio was posted by on a Twitter account recently announced by an al-Shabab spokesperson as legitimate. Previously, there have been a number of Twitter accounts claiming to be linked to the terror group that have provided unverified information.

The President of Kenya, Uhuru Kenyatta, announced the end of the crisis today, saying 61 civilians and six responding security forces soldiers had been killed in the days since a group of al-Shabab fighters opened fire in Nairobi's upscale Westgate mall Saturday. Five of the alleged attackers were killed and 11 others are in custody, Kenyatta said.

Al-Shabab, a Somalia-based terrorist group that has allied itself with al Qaeda, controlled much of southern Somalia including the nation's capital Mogadishu until a force of African Union troops, including Kenyans, pushed the terror group out in 2011 and 2012.

Earlier today, the new Twitter account allegedly belonging to al-Shabab said, "You could have avoided all this and lived your lives with relative safety. Remove your forces from our country and peace will come."

"The despicable perpetrators of this cowardly act hope to intimidate, divide and cause despondency amongst Kenyans," he said. "We have overcome terrorist attacks before. In fact, we have fought courageously and defeated them within and outside our borders. We will defeat them again."

ABC News' Rym Momtaz contributed to this report.

[Editor's Note: A previous version of this report listed the civilian death toll at 62, based on earlier statements from the Kenyan government. This report has been updated with information from President Kenyatta.]